3.7 kbp of cDNA previously found to encode the head region of chicken brain nonmuscle myosin heavy chain (a B isoform of vertebrate nonmuscle myosin II heavy chain) was inserted into the insect vector pBlueBac and will be transfected into insect cells with the purpose of expressing mg quantities of the myosin heavy chain. Our goal is to recover a fully active nonmuscle myosin heavy chain so that we can examine the role of the myosin light chains on enzymatic activity as well as the effect of the inserted amino acid sequences we have recently discovered in the head portion of myosin cDNA cloned from a chicken brain library.